Hot hole-induced dissociation of NO dimers on a copper surface
- Surface Science Research Centre, University of Liverpool, Oxford Road, Liverpool L69 3BX (United Kingdom)
We use reflection-absorption infrared spectroscopy (RAIRS) to study the photochemistry of NO on Cu(110) in the UV-visible range. We observe that the only photoactive species of NO on Cu(110) is the NO dimer, which is asymmetrically bound to the surface. RAIRS shows that photoinduced dissociation proceeds via breaking of the weak N-N bond of the dimer, photodesorbing one NO{sub g} to the gas phase and leaving one NO{sub ads} adsorbed on the surface in a metastable atop position. We model the measured wavelength-dependent cross sections assuming both electron- and hole-induced processes and find that the photochemistry can be described by either electron attachment to a level 0.3 eV above the Fermi energy E{sub F} or hole attachment to a level 2.2 eV below E{sub F}. While there is no experimental or theoretical evidence for an electron attachment level so close to E{sub F}, an occupied NO-related molecular orbital is known to exist at E{sub F}- 2.52 eV on the Cu(111) surface [I. Kinoshita, A. Misu, and T. Munakata, J. Chem. Phys. 102, 2970 (1995)]. We, therefore, propose that photoinduced dissociation of NO dimers on Cu(110) in the visible wavelength region proceeds by the creation of hot holes at the top of the copper d-band.
- OSTI ID:
- 22038794
- Journal Information:
- Journal of Chemical Physics, Vol. 135, Issue 22; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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